A non-volatile semiconductor memory (NVSM) module may be employed as mass storage for a computer system (e.g., desktop, laptop, portable, etc.) or a consumer device (e.g., music player, cell phone, camera, etc.) or other suitable application. The NVSM module may comprise one or more memory devices (such as a flash memory) and memory controller for accessing each memory device via a channel including an I/O bus. The memory controller may receive commands, such as write or read commands from a host and submit each command to a memory device. When submitting a write command to a memory device, the memory controller transfers the address and the write data over the I/O bus. When submitting a read command, the memory controller transfers the address over the I/O bus and then receives the read data over the I/O bus.
However, the host may perform reads and writes to any physical location in the one or more memory devices via respective read and write commands. Consequently, it is the responsibility of the memory controller to ensure that all of the commands are performed on the one or more memory devices in the order dictated by the host. This is commonly achieved by using a command based coherency scheme. However, if multiple host commands are accessing a common physical area of a memory device, the command based coherency scheme requires that the commands be executed one at a time, in the same order in which the commands are received.